Synopsis: Searching for Dark Matter in Exoplanet Data

A satellite currently hunting for planets around distant stars could potentially spot black holes that some theories take for the missing dark matter.
Synopsis figure
NASA/Carter Roberts

Our galaxy could be filled with asteroid-size black holes that presumably formed shortly after the big bang. If they exist in large numbers, these so-called primordial black holes would serve as the dark matter that keeps stars gravitationally glued inside galaxies. None of these primordial black holes have been detected so far, but a new theoretical analysis described in Physical Review Letters demonstrates that a current planet-hunting mission is well placed to search for them.

As dark matter candidates go, primordial black holes are widely considered to be the dark horse. Previous astronomical searches for these objects came up empty, so many cosmologists put their money on the alternative candidate: a weakly interacting particle that physicists hope to find in accelerators or other experiments.

Still, there is a mass range of relatively small primordial black holes that has yet to be ruled out. Kim Griest, of the University of California in San Diego, and colleagues believe that part of this “observational gap” could be explored by piggybacking on a separate astronomy survey. NASA’s Kepler satellite was designed to search for planets around 150,000 stars (in a single field of view) that are relatively close to Earth. A planet passing in front of one of these stars dims the starlight by a small amount. Conversely, a black hole passing between us and a Kepler star would have the opposite effect: it would act as a lens and brighten the starlight. The authors calculate that Kepler is the first instrument sensitive enough to detect this so-called microlensing for black holes with masses of around 0.1% of an Earth mass. – Michael Schirber


Announcements

More Announcements »

Subject Areas

Particles and FieldsCosmology

Previous Synopsis

Nonlinear Dynamics

You Don’t Cite Me Anymore

Read More »

Next Synopsis

Related Articles

Focus: Low Cost Polarized Positrons
Particles and Fields

Focus: Low Cost Polarized Positrons

A new technique requires much less energy to produce a beam of polarized positrons than previous techniques, making such beams potentially more widely available. Read More »

Synopsis: Lightweight Particles Might Explain Missing Lithium
Cosmology

Synopsis: Lightweight Particles Might Explain Missing Lithium

The apparent lack of lithium in the Universe, relative to theoretical expectations, could be explained by hypothetical lightweight and electrically neutral particles. Read More »

Synopsis: Cosmic Magnetism Revisited
Cosmology

Synopsis: Cosmic Magnetism Revisited

An analysis of the polarized emission from some 3000 distant radio sources places a stringent upper limit on the strength of the cosmological magnetic field. Read More »

More Articles